/*
 * Copyright (C) 2012 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.manning.androidhacks.hack040.util;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.util.Log;
import android.widget.Toast;

import com.manning.androidhacks.hack040.BuildConfig;

/**
 * A simple subclass of {@link ImageResizer} that fetches and resizes images
 * fetched from a URL.
 */
public class ImageFetcher extends ImageResizer {
  private static final String TAG = "ImageFetcher";

  /**
   * Initialize providing a target image width and height for the processing
   * images.
   * 
   * @param activity
   * @param imageWidth
   * @param imageHeight
   */
  public ImageFetcher(Activity activity, int imageWidth, int imageHeight) {
    super(activity, imageWidth, imageHeight);
    init(activity);
  }

  /**
   * Initialize providing a single target image size (used for both width and
   * height);
   * 
   * @param activity
   * @param imageSize
   */
  public ImageFetcher(Activity activity, int imageSize) {
    super(activity, imageSize);
    init(activity);
  }

  private void init(Context context) {
    checkConnection(context);
  }

  /**
   * Simple network connection check.
   * 
   * @param context
   */
  private void checkConnection(Context context) {
    final ConnectivityManager cm = (ConnectivityManager) context
        .getSystemService(Context.CONNECTIVITY_SERVICE);
    final NetworkInfo networkInfo = cm.getActiveNetworkInfo();
    if (networkInfo == null || !networkInfo.isConnectedOrConnecting()) {
      Toast.makeText(context, "No network connection found.",
          Toast.LENGTH_LONG).show();
      Log.e(TAG, "checkConnection - no connection found");
    }
  }

  /**
   * The main process method, which will be called by the ImageWorker in the
   * AsyncTask background thread.
   * 
   * @param data
   *          The data to load the bitmap, in this case, a regular http URL
   * @return The downloaded and resized bitmap
   */
  private Bitmap processBitmap(String data) {
    if (BuildConfig.DEBUG) {
      Log.d(TAG, "processBitmap - " + data);
    }

    // Download a bitmap, write it to a file
    final File f = downloadBitmap(mActivity, data,
        mImageCache.getDiskCache());

    if (f != null) {
      // Return a sampled down version
      return decodeSampledBitmapFromFile(f.toString(), mImageWidth,
          mImageHeight);
    }

    return null;
  }

  @Override
  protected Bitmap processBitmap(Object data) {
    return processBitmap(String.valueOf(data));
  }

  /**
   * Download a bitmap from a URL, write it to a disk and return the File
   * pointer. This implementation uses a simple disk cache.
   * 
   * @param context
   *          The context to use
   * @param urlString
   *          The URL to fetch
   * @param cache
   *          The disk cache instance to get the download directory from.
   * @return A File pointing to the fetched bitmap
   */
  public static File downloadBitmap(Context context, String urlString,
      DiskLruCache cache) {
    final File cacheFile = new File(cache.createFilePath(urlString));

    if (cache.containsKey(urlString)) {
      if (BuildConfig.DEBUG) {
        Log.d(TAG, "downloadBitmap - found in http cache - "
            + urlString);
      }
      return cacheFile;
    }

    if (BuildConfig.DEBUG) {
      Log.d(TAG, "downloadBitmap - downloading - " + urlString);
    }

    Utils.disableConnectionReuseIfNecessary();
    HttpURLConnection urlConnection = null;
    BufferedOutputStream out = null;

    try {
      final URL url = new URL(urlString);
      urlConnection = (HttpURLConnection) url.openConnection();
      final InputStream in = new BufferedInputStream(
          urlConnection.getInputStream(), Utils.IO_BUFFER_SIZE);
      out = new BufferedOutputStream(new FileOutputStream(cacheFile),
          Utils.IO_BUFFER_SIZE);

      int b;
      while ((b = in.read()) != -1) {
        out.write(b);
      }
      cache.putFromFetcher(urlString);
      return cacheFile;

    } catch (final IOException e) {
      Log.e(TAG, "Error in downloadBitmap - " + e);
    } finally {
      if (urlConnection != null) {
        urlConnection.disconnect();
      }
      if (out != null) {
        try {
          out.close();
        } catch (final IOException e) {
          Log.e(TAG, "Error in downloadBitmap - " + e);
        }
      }
    }

    return null;
  }
}
